Efficacy of belimumab in two serologically distinct high disease activity subgroups of patients with systemic lupus erythematosus: post-hoc analysis of data from the phase III programme

Abstract

Objective To assess the appropriateness of expanded serological activity eligibility criteria for belimumab use in the UK systemic lupus erythematosus (SLE) population (and possibly other countries), which includes patients with either anti-double-stranded DNA (anti-dsDNA) positivity or hypocomplementaemia rather than both criteria.Methods This post-hoc analysis used data from three randomised, double-blind, placebo-controlled phase III belimumab trials: BLISS-52 (BEL110752; NCT00424476), BLISS-76 (BEL110751; NCT00410384) and BLISS-SC (BEL112341; NCT01484496). Patients with SLE were stratified by high disease activity (HDA): HDA1, Safety of Estrogens in Lupus Erythematosus National Assessment-SLE Disease Activity Index (SELENA-SLEDAI) score ≥10, low complement and positive anti-dsDNA; and HDA2, SELENA-SLEDAI ≥10 and either low complement or positive anti-dsDNA.Results This analysis included 660 HDA1 patients (n=396 on intravenous treatment; n=264 on subcutaneous treatment) and 969 HDA2 patients (n=532 on intravenous treatment; n=437 on subcutaneous treatment). Significant improvements were observed at week 52 with belimumab versus placebo, irrespective of subgroups or drug formulations, in SLE Responder Index (SRI) 4 response (OR (95% CI): HDA1 intravenous 2.7 (1.8 to 4.1); HDA2 intravenous 2.3 (1.61 to 3.26); HDA1 subcutaneous 2.2 (1.22 to 3.85); HDA2 subcutaneous 1.8 (1.17 to 2.74)); proportion of patients achieving ≥4-point reduction in SELENA-SLEDAI score (OR (95% CI): HDA1 intravenous 2.6 (1.7 to 3.9); HDA2 intravenous 2.1 (1.49 to 3.03); HDA1 subcutaneous 2.3 (1.30 to 4.14); HDA2 subcutaneous 1.9 (1.21 to 2.84)); patients with no worsening in Physician Global Assessment (OR (95% CI): HDA1 intravenous 2.0 (1.3 to 3.1); HDA2 intravenous 1.7 (1.17 to 2.45); HDA1 subcutaneous 2.3 (1.18 to 4.40); HDA2 subcutaneous 1.8 (1.11 to 2.92)); and risk of severe flares (HR (95% CI): HDA1 intravenous 0.6 (0.37 to 0.81); HDA2 intravenous 0.6 (0.43 to 0.86); HDA1 subcutaneous 0.52 (0.30 to 0.92); HDA2 subcutaneous 0.59 (0.37 to 0.94)).Conclusion Broadening the HDA population to include either low complement or positive anti-dsDNA, rather than both, would enable more UK patients to receive SLE treatment and experience improved clinical outcomes.